android.os.NetworkOnMainThreadException in API call

Question

I was learning how to make an api call in android. This is my fragment. I have uploaded this json file in myjson.com. From my fragment class, I tried to hit the api. I believe the response should return the data inside the json object to my log.

public class TableFragment extends android.support.v4.app.Fragment {

public TableFragment() {
}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {

    View rootView = inflater.inflate(R.layout.fragment_table, container, false);

    Button api_btn = (Button)rootView.findViewById(R.id.enter_button);
    api_btn.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {

            try {
                URL url = new URL("https://api.myjson.com/bins/n80yl");
                HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
                try {
                    BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(urlConnection.getInputStream()));
                    StringBuilder stringBuilder = new StringBuilder();
                    String line;
                    while ((line = bufferedReader.readLine()) != null) {
                        stringBuilder.append(line).append("\n");
                    }
                    bufferedReader.close();
                    Log.d("tagg", "onClick: "+stringBuilder);
                }catch (Exception e)
                {
                    Log.d("tagg", "onClick:exception1  "+e);
                }
                finally{
                    urlConnection.disconnect();
                }
            }
            catch(Exception e) {
                Log.d("tagg", "doInBackground:exception2 "+e);

            }
        }
    });


    return rootView;
}

}

i have given the internet permission in manifest.

Is this the correct way so that i can learn the api mechanism in android. thanks in advance

it's enough perform some search inside S.O. this question is Android basics. Look here https://stackoverflow.com/questions/6343166/how-do-i-fix-android-os-networkonmainthreadexception — an_droid_dev, Sep 15 '17 at 07:58

score 0 · Accepted Answer · answered Sep 15 '17 at 07:56

The exception that is thrown when an application attempts to perform a networking operation on its main thread. ref

So you need to move to move to a background process (thread):

Best way would be to use AsyncTask

AsyncTask enables proper and easy use of the UI thread. This class allows you to perform background operations and publish results on the UI thread without having to manipulate threads and/or handlers.

So if you move this code to AsyncTask it should work.

URL url = new URL("https://api.myjson.com/bins/n80yl");
                HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
                try {
                    BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(urlConnection.getInputStream()));
                    StringBuilder stringBuilder = new StringBuilder();
                    String line;
                    while ((line = bufferedReader.readLine()) != null) {
                        stringBuilder.append(line).append("\n");
                    }
                    bufferedReader.close();
                    Log.d("tagg", "onClick: "+stringBuilder);
                }catch (Exception e)
                {
                    Log.d("tagg", "onClick:exception1  "+e);
                }
                finally{
                    urlConnection.disconnect();
                }
            }
            catch(Exception e) {
                Log.d("tagg", "doInBackground:exception2 "+e);

            }

Don't forget to add the internet permission to your Manifest.xml file

<uses-permission android:name="android.permission.INTERNET" />

i do it on my on click i have given it public void onClick(View v) { getContext().startService(new Intent(getContext(), RetrieveFeedTask .class)); } — Martin j, Sep 15 '17 at 08:01
Actually in my fragment class in on click i have given this line getContext().startService(new Intent(getContext(), RetrieveFeedTask.class)); — Martin j, Sep 15 '17 at 08:09
but i think passing the intent to a asynctask is not this way ... that is my error now — Martin j, Sep 15 '17 at 08:10
Then this is a different topic which needs a different question — Yamen Nassif, Sep 15 '17 at 08:11
Please add your current code to a new question and also add the error. its pretty much hard to read in the comments. — Yamen Nassif, Sep 15 '17 at 08:11

android.os.NetworkOnMainThreadException in API call

1 Answers1